There are some questionable parts in there, in my opinion. For example, why building your own tool to "guess" where an app connects to if you could use a network monitoring tool. However, those are not directly related to the main topic.
An interesting part is how folks in Monzo "reverted" the idea behind Network Policies using templating. So, instead of a target services allowing internal connections, a caller can specify the groups of services it wants to connect to.
Although, I think it partially negates the idea of Network Policies, I can completely understand, why Monzo did that from the UX perspective.
Also, here's a Reddit discussion on the topic. I love the top comment there:
How would you even know that another team plans to connect your apps?
- By communicating...
#kubernetes #networking